N-硬脂酰-L-谷氨酸及其乙酯衍生物的合成与成胶性质研究

Synthesis and Gelation of N-Stearoyl-L-glutamic Acid and N-Stearoyl-L-glutamic Diethyl Ester

研究了N 硬脂酰 L 谷氨酸 (C1 8 Glu)———一个具有多个氢键位点的有机胶凝剂分子及其乙酯 (C1 8 Glu 2ES)衍生物的合成与成胶性质 .文献报道的合成方法是将硬脂酰氯滴加到L 谷氨酸钠的丙酮与水的混合溶液中 ,但我们的多次实验结果表明该合成方法的可操作性比较差 ,究其原因主要在于 :反应的副产物之一盐酸的强酸性容易导致反应液的局部强酸性环境 ,而使反应产生的C1 8 Glu分子继续与L 谷氨酸反应 ,这大大增加了产物的后处理难度 ,很难得到高纯度的产物 .因此 ,我们改用L 谷氨酸二乙酯为原料 ,在二环己基碳酰亚胺催化下或通过硬脂酰氯得到所需的高纯度产物 .在此基础上 ,研究了合成的C1 8 Glu及C1 8 Glu 2ES的成胶性质 ,结果表明C1 8 Glu 2ES具有比C1 8

Synthesis of N-stearoyl-L-glutamic acid (C-18-Glu), a new gelator with multi-H-bonding sites, and N-stearoyl-L-glutamic diethyl ester (C-18-Glu-2ES) were reported. The previously reported synthetic route of C-18-Glu is that stearoyl chloride was dropwise added into disodium L-glutamate solution in a mixture of acetone and water (J. Am. Oil Chem. Soc. 1972, 49, 157 and Langmiur, 2001, 17, 1317). However, our experimental results indicated that one of the by-product HCl, could catalyze the yielded C-18-Glu to react further with L-glutamate to give more side-products. Therefore, the further workup became more difficult and the pure C-18-Glu was difficult to be obtained. Here, we synthesized C-18-Glu by the following two routes. One is from L-glutamic diethyl ester and steanic acid using dicyclohexylcarbodiimide (DCC) as a catalyzer. The other is from stearoyl chloride and L-glutamic diethyl ester. These two synthetic routes can all give out C-18-Ghr with satisfactory characteristic data. Moreover, The gelating properties of C-18-Ghr and C-18-Glu-2ES were also investigated. C-18-Glu can gel chloroform and 1 : 1 mixed ethanol/ water, while C-18-Glu-2ES can form organogels in more solvents such as petroleum ether, hexane, acetone, ethanol, and 3:7 mixed ethanol/water. AFM images indicated that C-18-Glu self-assembled into nanowires in chloroform, while C-18-Glu-2ES into lamellar-like microstructures in 3:7 mixed ethanol/water.